Pump piston



55 invention,

Patented Dec. 25, 1923.

uN-rrno I srAT-es PATENT, OFF/ICE.

CHARLES E. EBAZIER, or BRECKENRIDGE, TEXAS;

PUMP PISTON.

Application filed August 10, 1922. SeriaLNo. 580,866.

To all whom it may mm- Be it known that I, CHARLES E. FRAZIER, a citizen of the United States, residing at Breckenridge, in the county of Stephensa'nd State of Texas, have invented certain new and useful Improvements in'Pump Pistons, of which the following is a specification.

This invention relates to new and useful improvements in pump pistons and particularly to such pistons as are used in the working valve in'wells. a

In this type of piston it is customary to use cups of flexible material and to provide. means for expanding these cups into contact with the inner surface or 'wall of the valve.

However, such means as have beenheretoforefused do notprovide an evenor ample expansion of the cup so that only the upper edges or a portion of the cup is brought into contact with the valve. Such a procedure necessitates more frequent expanding and does not utilize the entire wearingfsurface of the cup.

The object of my invention is to provide intermediate expanding means disposed between the expanding element and the cup whereby expanding said means the cupi's given a more extended expansionwhereby substantially its "entire surface is brought into contactwith the valve. A further object is to provide means for holding the cup in expanded position and providing for an increased expansion to compensate wear.

In carrying out the invent-ionI provide for each cup a resilient shim having longitudinal fingers whereby it may be readily expanded so as to expandthe cup. By this arrangement the expanding element may have an acute angle while the surface of the shim may be disposed at a very slight angle to theperpendicular and thus a slight move-' ment of the expanding element will expand the shim to the necessary extent.

A construction designed to carry out the invention will be hereinafterdescribed together with other featuresof the invention.

The invention will be more readily understood from a reading. of the following specification and by reference to the accompanye'o ing drawings, in which an example of the invention is shown andwherein:

Fig. 1 is a view showing a working valve in vertical section and a piston therein in elevation constructed in accordance with my Fig. 2 is a sectional detail showing the expanding element, and

Fig. "3 is a sectional detail of the fastening means for holding the parts after they have been expanded. A

In the drawings the numeral 10 designates a tubular shank ormttn'drelforniing the core of the piston. At it upper end it is providedwith a screw threadedhead 11 which is inserted in the lower end of a valve cage 12. Immediately below the head is arranged a collar 13 which isjprovided with circumferential'p'acking ringsl l of the usual type. Justbelow the collar an annular follower or wet ge shaped ring 15 is loosely mounted on the mandrel. Usually this ring has its lower end telescoping into the upper end of a packing cup 16 which is usually formed of rubber, leather or other flexible material. As

is shown in Fig. 2 the upper edge ofthecup cal slots 18 extending fr'om near its lower end to its upper end. I The lower ends 'of the slot are bored out so that the ,fingers produced by the slot may be expanded and contracted without danger ofsplitting the shim. The shim is preferably made of resilient metal but this is not absolutely necessary. The shim fits snugly but loosely on the mandrel 10 and within \the'cup 16. At its upper end it has an inwardly inclined-angular shoulder 28 which receives the lower end of the ring 15. I i I The angular inclination of the ring is much more acute than the outer surface of the shim and the shoulder 28 has substantially the same angular'ity as the ring. Consequently when the ring. is forced ,d0wn Wardly it. ride over the shoulder 28 and forces the fingers of the shim outwardly whereby the cup 16 is expanded. As substantially the entire length of the shim is expanded it will be seen that a greater portion of the surf-ace of the cup will be expanded and thus instead of only its upper edge being extended, as would be the case 2 where only the ring 15 was relied upon, a large portion of its surface is pressed into contact with the working valve.

The piston is made up of a plurality of the elements 15, 16 and 17, each cup being supported upon a ring 15. This is true except in the case of the lowermost cup which rests upon a collar 19 having piston rings 20 similar to the collar 13. It is to be understood that the piston may be of any suitable length.

The lower end of the mandrel is provided on opposite sides with ratchet teeth 21 adapted to receive spring pressed dogs 22 engaging through slots 23 in the side of a cap 24. The cap 24: has diametrically opposite vertical slots 25 receiving studs 26 carried by the mandrel, whereby the cap may undergo a relative vertical movement without being displaced entirely from the mandrel. As the cap is moved-upwardly the dogs ride over the teeth and thus retain the cap in the position to which it is elevated. The

cap has inlet ports 27 at its lower end.

\Vhenever the cap is displaced upwardly all of the cups and rings and shims are likewise moved upwardly and consequently the shims are causedto ride up the inclined sides of the rings, whereby the cups are expanded. In placing the piston in the working valve the same is lowered until the cap strikes an obstruction in the bottom of the valve whereby it comes to rest. The mandrel is moved downwardly and the teeth ride under the dogs 22. The collar 19 supports the lower most cup and the collar 12 forces the upper most ring 15 down into the upper most shim 17, whereby the upper most cup 16 is expanded and a continued move ment forces the other rings and shims clownward whereby the cups are expanded as is obvious.

The parts are held in this pos ition'and when it is necessary to compensate for the wear of the cups it is merely necessary to jar down on the mandrel to increase the expansion of the shims and consequently the cups as is obvious. 7

Various changes in the size and shape of the dilferent parts as well as alterations and modifications may be made without departing from the spirit of the invention and within the scope of the appended claims.

What I claim, is: 1

1. In a working valve piston for pumps, a mandrel, a plurality of flexible cups mounted on the mandrel, aplurality of-expanding elements mounted on said mandrel, means for expanding the cup interposed between the elements and said cups, and means on the mandrel for fastening the parts in expanded positions.

1. In a pump piston for working valve,'a mandrel, a plurality of flexible cups mounted on the mandrel, an expansion element for each cup having an acute inclination, and

an expanding medium interposed between the cup and the element acting to increase the amplitude of expansion of the cup with respect to the expansive movement contributed to it by said element.

3. A pump piston for a working valve, a tubular mandrel, a plurality of flexible cups mounted on said mandrel, an expansible cylindrical shim mounted within each cup, and 'a wedge shape ring mounted on the mandrel above each shim and telescoping into the latter for expanding it and means for supporting theparts against movement when the mandrel is displaced for expanding the cups.

4:. A shim for a working valve piston in- I eluding a I cylindrical body havinglongitudinal slots whereby it may be expanded and provided with an angular inclined shoulder at its upper end. 1

5. In a pump piston for working valves, a tubular mandrel having a head at its upper end, a plurality of wedge shaped annular rings loosely mounted on the mandrel below the head and having a limited upward movement with relation to said mandrel, a plurality or" flexible cups. one being associated with each ring, a plurality of cylindrical shims, one fitting in each cup and having its upper end receiving the lower end of a superimposed ring, a cap loosely confined on the lower end of the mandrel, and means for holding the cap in thepositionv to which it is adjusted on said mandrel, said cap acting to support the cups and shims when the mandrel and rings are displaced downwardly.

6. In a pump piston, the combination of a mandrel, a plurality of flexible cups mounted on said mandrel, a plurality of concentric expanding members mounted on the mandrel, one within each cup, and a plurality of inclined concentric expanding elements, surrounding the mandrel between the cups, the lower end of each element engaging in the upper end of an expanding member.

7 In a pump piston the combination of a mandrel, a plurality of concentric flexible cups, a plurality oi": concentric expanding members mounted directly on the mandrel CHARLES E. FRAZIER. 

